1. Field of the Invention
The present invention relates to a composite material and a manufacturing method thereof, a substrate processing apparatus and a preparing method thereof, a substrate mounting stage and a preparing method thereof, and a substrate processing method.
2. Description of the Related Art
A recent ultra LSI is required to integrate more than million of elements in a chip of several square mm. The dry etching technique for achieving fine processing of an ultra LSI and the chemical vapor deposition (CVD) technique, one of the thin film forming techniques, are required to achieve a further higher accuracy, and there are proposed process resulting from contrivances in gas chemistry, plasma source and wafer temperature control.
For the manufacture of a semiconductor apparatus, there are available many processes of applying a plasma treatment to various semiconductor boards, wafers or various thin films formed thereon, including plasma etching and plasma CVD. These carious semiconductor boards, wafers and various thin films formed thereon may sometimes be collectively referred to as substrates. In these plasma treatment, particularly in plasma etching or the like, treatment while holding a substrate at a low temperature within a range of from room temperature to below 0xc2x0 C. is increasingly being adopted with a view to achieving a high processing accuracy. Importance of temperature control and temperature administration of substrate is now therefore being recognized.
Along with the progress made in multi-layer wiring technology in the area of semiconductor apparatus, there is a demand for using copper (Cu) as a material for wiring for the purpose of reducing wiring resistance or improving resistance to electro-migration, and technical development efforts are made to appropriately dry-etch a wiring material composing copper. There is another demand for adopting high-density plasma CVD in gap filling technology. As a result, not only the processes for plasma treatment at room temperature or at a lower temperature, but also processes of applying a plasma treatment while holding a substrate at a high temperature are having an increasing importance.
In such a plasma treatment at a high temperature, however, there occurs a considerable heat input from the plasma into the substrate as a result of ionic impact to the substrate in etching, or irradiation of a high-density plasma onto the substrate in filling CVD. Consequently, the substrate temperature may be raised by 40xc2x0 C. to 100xc2x0 C. as compared with that before generation of plasma. In a process of heating the substrate by a substrate mounting stage (such as a wafer stage) holding the substrate, to apply a plasma treatment at a high temperature, therefore, it is technically important to inhibit the influence of heat input from plasma into the substrate and control the substrate at a set temperature at a high accuracy.
Control of side wall and ceiling plate is also important as one of the process control parameters in various substrate processing apparatuses such as an etching unit and a CVD unit. Control of upper opposite electrode in an etching unit is also important. Reaction products produced in etching or CVD tend to accumulate on side wall, ceiling plate and upper opposite electrode (these may sometimes be referred to as xe2x80x9cside wall and the likexe2x80x9d) of these apparatuses. When the thus accumulating reaction products peel off from the side walls and the like of the apparatus, this may lead to a particle-level deterioration. Or, when a processor such as a polymer accumulates on the side wall and the like of an etching unit during etching of an oxide film, the side wall and the like serve as a scavenger of fluorocarbon polymer precursor, resulting in a variation in the ratio of carbon to fluorine in plasma, thus causing a problem of deterioration of etching property. It is therefore a common practice to adopt a technique for presenting accumulation by causing separation of the accumulating precursor through heating of the side wall and the like to a high temperature and irradiation onto the side wall and the like of the etching unit.
In the conventional art, temperature control of a substrate at high temperature is far from being sufficient. In the conventional art, occurrence of heating of the substrate to the aforesaid extent during processing is deemed to be natural, and temperature of the substrate mounting stage is previously set at a low temperature with heating of the substrate in view. Proceeding of the process in an anticipation of such heating results in many problems to be solved, including an extended period of processing time, a decrease in throughput, and deterioration of reproducibility and controllability of the process as a result of considerable variation of temperature.
A conceivable means for solving these problems is to mount an electrostatic chuck onto the substrate mounting stage to be heated to a high temperature. In order to mount an electrostatic chuck onto the substrate mounting stage, however, there is an important problem of how to connect the heated substrate mounting stage and a dielectric body composing the electrostatic chuck. This problem has prevented practical application of a substrate mounting stage having an electrostatic chuck mounted thereon. More specifically, in a substrate mounting stage based on high-temperature specifications, it is necessary to efficiently conduct heat to the substrate upon attracting the substrate and securing it onto the substrate mounting stage via the electrostatic shuck. The substrate mounting stage and the electrostatic chuck must therefore be connected with a good heat conductivity.
As a material for the substrate mounting stage in a substrate processing apparatus such as an etching unit, a CVD unit or a sputtering unit, it is common to adopt aluminum (Al) for a high heat conductivity and easy processing. Aluminum has a linear expansion coefficient of about 23xc3x9710xe2x88x926/K. In general a ceramics material is used as a dielectric body composing the electrostatic chuck. When directly connecting the substrate mounting stage and the electrostatic chuck, therefore a damage such as cracks is caused in the ceramics material by heating and cooling of the substrate mounting stage as a result of the difference in linear expansion coefficient between the ceramics material composing the electrostatic chuck and aluminum composing the substrate mounting stage, resulting in a problem of breakage of the electrostatic chuck.
It is therefore a usual practice to fix the electrostatic chuck to the substrate mounting stage by means of screw-fitting or the like. In this structure, however, evacuation of the substrate processing apparatus causes vacuum isolation of the connection interface between the electrostatic chuck and the substrate mounting stage, resulting in a degraded efficiency of heat exchange between the substrate mounting stage and the substrate via the electrostatic chuck. As a result, the substrate suffers heat from plasma, leading to heating of the substrate to a temperature over the set temperature.
The side wall and the like of the substrate processing apparatus are usually made of stainless steel or aluminum. It is therefore a common practice, during etching, to form an Al2O3 layer (alumite layer) on the surface of the side wall and the like made of aluminum with a view to preventing occurrence of metal contamination caused by the side wall and the like directly exposed to plasma or preventing corrosion of the side wall and the like by a halogen gas. When the side wall is made of stainless steel, and Al2O3 reflector is provided near the side wall in the interior of the substrate processing apparatus.
When the substrate processing apparatus is heated in this state, with side wall and the like made of aluminum, cracks tend to be caused in an Al2O3 layer formed on the surface of the side wall and the like, as a result of the difference in linear expansion coefficient between aluminum and Al2O3. When an Al2O3 reflector is arranged near the side wall in the interior of the substrate processing apparatus, it is difficult to sufficiently heat the reflector from outside the substrate processing apparatus. That is, it is difficult to heat the reflector to a temperature permitting allout separation of the precursor entering the reflector therefrom. It is possible only to heat the reflector to about 100xc2x0 C. at the most.
The various problems involved in the manufacture of a semiconductor apparatus have been described above. In many sectors of industry, there is an increasing demand for development of a technology capable of solving these problems, i.e., proving a composite material which permits effective avoidance of occurrence of damages to a ceramics material caused by the difference in linear expansion coefficient between different materials in a composite material comprising a metallic material having a ceramics material formed thereon, or metal contamination or corrosion in environments of use of a composite material.
An object the present invention is therefore to provide composite material and a manufacturing method thereof, a substrate processing apparatus using such a composite material and manufacturing method thereof, a substrate mounting stage and a manufacturing method thereof, and a substrate processing method using such a substrate processing apparatus, which permit avoidance of occurrence of a damage caused by the difference in thermal expansion between materials, sufficient withstanding of the use at high temperatures, prevention of occurrence of metal contamination, provide a high corrosion resistance, and enable, for example, high-temperature processing of a substrate.
The composite material of the invention to achieve the foregoing object comprises a matrix comprising a ceramics member having a texture filled with an aluminum-based material, and a ceramics layer provided on the surface of the matrix.
The composite material of the invention to achieve the foregoing object composes a part of a processing apparatus for processing a substrate, and comprises a matrix comprising a ceramics member having a texture filled with an aluminum-based material, and a ceramics layer provided on the surface of the matrix. In this substrate processing apparatus, for example, plasma etching, plasma CVD or sputtering is applied to the substrate. A part of the substrate processing apparatus made of a composite material may take the form of a substrate mounting stage having an electrostatic chucking function and provided with temperature control means. Or, in the substrate processing apparatus, for example, plasma etching or plasma CVD is applied to the substrate. A part of the substrate processing apparatus made of a composite material may take the form of side walls and/or a ceiling plate of the substrate processing apparatus. Further, in the substrate processing apparatus, for example, plasma etching is applied to the substrate, and apart of the substrate processing apparatus made of a composite material may take the form of parallel and flat upper opposed electrodes.
The substrate processing apparatus for processing the substrate of the invention to achieve the foregoing object comprises a composite material comprises a matrix consisting of a ceramics member having a texture filled with an aluminum-based material, and a ceramics layer provided on the surface of the matrix.
In the substrate processing apparatus of the invention, for example, plasma etching, plasma CVD or sputtering is applied to the substrate, and a part of the substrate processing apparatus made of a composite material may take the form of a substrate mounting stage having an electrostatic chucking function and provided with temperature control means. This substrate processing apparatus may sometimes be hereinafter referred to as the substrate processing apparatus of the first embodiment of the invention. In this case, the substrate mounting stage may be used as an electrode, in which case, the ceramics layer displays the electrostatic chucking function.
In the substrate processing apparatus of the embodiment 1 of the invention, temperature control means should preferably be provided in the substrate mounting stage for accurate and rapid temperature control of the substrate mounting stage, and further, this temperature control means should preferably be composed of a heater, and the heater may be arranged outside the composite material, or may be provided in the interior of the matrix. In the latter case, when assuming the matrix to have a linear expansion coefficient xcex11[unit: 10xe2x88x926/K], the material composing the heater should preferably have a linear expansion coefficient xcex1H[unit: 10xe2x88x926/K] satisfying (xcex11xe2x88x923)xe2x89xa6xcex1Hxe2x89xa6(xcex11+3). The term the material composing the heater means the material composing a part (for example, a sheath) of the heater in contact with the heater. This applies also in the description hereafter. Further, the temperature control means should preferably be composed of a piping for the flow of a temperature controlling heat medium, provided in the interior of the matrix. In this case, when assuming the matrix to have a linear expansion coefficient xcex11[unit: 10xe2x88x926/K], the piping should preferably have a linear expansion coefficient xcex1P[unit: 10xe2x88x926/K] satisfying (xcex11xe2x88x923)xe2x89xa6xcex1Hxe2x89xa6(xcex11+3). As a result of the linear expansion coefficient xcex11 of the matrix and the linear expansion coefficients xcex1H and xcex1P satisfying these relations as described above, it is possible to effectively present occurrence of a damage to the ceramics layer. When assuming an object to have a length L, a length at 0xc2x0 C. of L0 and xcex8 is temperature, in general, the linear expansion coefficientxcex1 can be expressed by xcex1=(dL/dxcex8)/L0, in units of Kxe2x88x921(1/K). In this specification, the linear expansion coefficient is expressed in unit of 10xe2x88x926/K. Hereafter, the linear expansion coefficient may sometimes be explained by omitting the unit.
Or, in the substrate processing apparatus of the invention, for example, plasma etching or plasma CVD is applied to the substrate, and a part of the substrate processing apparatus made of the composite material may take the form of side wall and/or a ceiling plate of the substrate processing apparatus. Such a substrate processing apparatus may hereafter be referred to as the substrate processing apparatus of the second embodiment of the invention. In this case, temperature control means should preferably be provided for the side walls and/or the ceiling plate of the substrate processing apparatus, and further, this temperature control means should preferably comprises a heater. As a result, for example, it is possible to heat the side walls and/or the ceiling plate to a temperature enabling a precursor entering the surface of the side walls and/or the ceiling plate of the processing apparatus to leave the side walls and/or the ceiling plate of the substrate processing apparatus. The heater may be arranged outside the composite material, or may be provided in the interior of the matrix. In the latter case when assuming the matrix to have a linear expansion coefficient xcex11[unit: 10xe2x88x926/K], the material composing the heater should preferably have a linear expansion coefficient xcex1H[unit: 10xe2x88x926/K] satisfying (xcex11xe2x88x923)xe2x89xa6xcex1Hxe2x89xa6(xcex11+3). As a result of the linear expansion coefficient xcex11 of the matrix and the linear expansion coefficient xcex1H of the material composing the heater satisfying these relations, it is possible to effectively prevent occurrence of a damage to the ceramics layer.
Or, in the substrate processing apparatus of the invention, for example, plasma etching is applied to the substrate, and apart of the substrate processing apparatus made of the composite material may take the form of a parallel flat upper opposite electrode provided in the substrate processing apparatus. Such a substrate processing apparatus may sometimes be referred to hereafter as the substrate processing apparatus of the embodiment 3 of the invention. In this case, temperature control means should preferably be provided for the upper opposite electrode, and further, this temperature control means should preferably comprise a heater. As a result, it is possible to heat the upper opposite electrode to a temperature enabling the precursor entering the surface of the upper opposite electrode to leave the upper opposed electrodes. The heater may be arranged outside the composite material, or in the interior of the matrix. In the latter case, when assuming the matrix to have a linear expansion coefficient xcex11[unit: 10xe2x88x926/K], the material composing the heater should preferably have a linear expansion coefficient xcex1H[unit: 10xe2x88x926/K] satisfying (xcex11xe2x88x923)xe2x89xa6xcex1Hxe2x89xa6(xcex11+3). As a result of the linear expansion coefficient xcex11 of the matrix and the linear expansion coefficient xcex1H of the material composing the heater satisfying the foregoing relation, it is possible to effectively prevent occurrence of a damage to the ceramics layer.
When applying plasma etching to the substrate in the substrate processing apparatus, it is possible to adopt the combination of the substrate processing apparatus of the embodiment 1 and the substrate processing apparatus of the embodiment 2, the combination of the substrate processing apparatus of the embodiment 1 and the substrate processing apparatus of the embodiment 3, the combination of the substrate processing apparatus of the embodiment 2 and the substrate processing apparatus of the embodiment 3, or the combination of the substrate processing apparatus of the embodiment 1, the substrate processing apparatus of the embodiment 2 and the substrate processing apparatus of the embodiment 3. When applying plasma CVD to the substrate in the substrate processing apparatus, it is possible to use the combination of the substrate processing apparatus of the embodiment 1 and the substrate processing apparatus of the embodiment 2.
The substrate mounting stage having an electrostatic chucking function and provided with temperature control means of the invention to achieve the foregoing object comprises a composite material consisting of a matrix comprising a ceramics member having a texture filled with an aluminum-based material and a ceramics layer provided on the surface of the matrix.
In the substrate mounting stage of the invention, the substrate mounting stage can be used as an electrode, and in this case, the ceramics layer displays an electrostatic chucking function. Temperature control means should preferably be provided for the purpose of accurately and rapidly carrying out temperature control, and further, this temperature control means should preferably comprise a heater. The heater may be arranged outside the composite material, or in the interior of the matrix. In the latter case, when assuming the matrix to have a linear expansion coefficient xcex11[unit: 10xe2x88x926/K], the material composing the heater should preferably have a linear expansion coefficient xcex1H[unit: 10xe2x88x926/K] satisfying (xcex11xe2x88x923)xe2x89xa6xcex1Hxe2x89xa6(xcex11+3). Further, it should preferably comprise a piping for the flow of a temperature controlling heat medium provided in the interior of the matrix. When assuming the matrix to have a linear expansion coefficient xcex11[unit: 10xe2x88x926/K], the piping should preferably have a linear expansion coefficient xcex1P[unit: 10xe2x88x926/K] satisfying (xcex11xe2x88x923)xe2x89xa6xcex1Pxe2x89xa6(xcex11+3).
In the composite material, the substrate processing apparatus or the substrate mounting stage of the invention, when assuming the matrix to have a linear expansion coefficient xcex11[unit: 10xe2x88x926/K], the ceramics layer should preferably have a linear expansion coefficient xcex12[unit: 10xe2x88x926/K] satisfying (xcex11xe2x88x923)xe2x89xa6xcex12xe2x89xa6(xcex11+3). As a result of xcex11 and xcex12 satisfying this relationship, it is possible to certainly prevent occurrence of damages such as cracks in the ceramics layer caused by the difference between the linear expansion coefficient xcex11 of the matrix and the linear expansion coefficient xcex12 of the ceramics layer.
In this case, the ceramics member composing the matrix may comprise cordierite ceramics; the aluminum-based material composing the matrix may comprise aluminum (Al) and silicon (Si); and the material composing the ceramics layer may comprise Al2O3. To adjust the linear expansion coefficient and electrical properties of the ceramics layer, for example, TiO2 may be added to the material composing the ceramics layer. It is desirable to select a volumetric ratio of cordierite ceramics to the aluminum-based material so as to satisfy (xcex11xe2x88x923)xe2x89xa6xcex12xe2x89xa6(xcex11+3). Or, the volumetric ratio of cordierite ceramics to the aluminum-based material should be within a range of from 25/75 to 75/25, or more preferably, from 25/75 to 50/50. By adopting a volumetric ratio within this range, not only the linear expansion coefficient of the matrix can be controlled, but also, the matrix has an electric conductivity and a heat conductivity closer to those of a metal rather than those of a pure ceramics. As a result, it is possible to apply voltage as well as bias to such a matrix. Further, when using the aluminum-based material as reference, the aluminum-based material should contain silicon in an amount within a range of from 12 to 35 vol. %, or preferably, from 16 to 35 vol. %, or more preferably, from 20 to 35 vol. % with a view to satisfying (xcex11xe2x88x923)xe2x89xa6xcex12xe2x89xa6(xcex11+3). Actually, the texture of the ceramics member in filled with aluminum (Al) and silicon (Si), and silicon (Si) is not contained in aluminum (Al). However, to express the volumetric ratio of silicon (Si) to aluminum (Al) in the aluminum-based material, an expression xe2x80x9csilicon is contained in the aluminum-based materialxe2x80x9d is used, and this applies also hereafter.
The ceramics member may be a fired form (sinter) of cordierite ceramics powder. However, the ceramics member should preferably be a fired (sintered) mixture of cordierite ceramics powder and cordierite ceramics filer with view to obtaining a porous ceramics member, and preventing occurrence of a damage to the ceramics member upon preparing the matrix. In the latter case, the ratio of cordierite ceramics filer in the fired mixture should be within a range of from 1 to 20 vol. %, or preferably, from 1 to 10 vol. %, or more preferably, from 1 to 5 vol. %. The average particle size of cordierite ceramics powder should be within a range of from 1 to 100 xcexcm, or preferably, from 5 to 50 xcexcm, or more preferably, from 5 to 10 xcexcm. Cordierite ceramics fiber should have an average diameter within a range of from 2 to 10 xcexcm, or preferably, form 3 to 5 xcexcm, and an average length within a range of from 0.1 to 10 mm, or preferably, from 1 to 2 mm. Further, the porosity of the ceramics member should be within a range of from 25 to 75%, or preferably, from 50 to 75%.
Or, the ceramics member composing the matrix may comprise aluminum nitride (AlN); the aluminum-based material composing the matrix may comprise aluminum (Al) or aluminum (Al) and silicon (Si); and the material composing the ceramics layer may comprise Al2O3 or aluminum nitride (AlN). To adjust the linear expansion coefficient and electrical properties of the ceramics layer, for example, TiO2 may be added to the material composing the ceramics layer. It is desirable to select a volumetric ratio of aluminum nitride to the aluminum-based material so as to satisfy (xcex11xe2x88x923)xe2x89xa6xcex12xe2x89xa6(xcex11+3). Or, the volumetric ratio of aluminum nitride to the aluminum-based material should be within a range of from 40/60 to 80/20, or more preferably, from 60/40 to 70/30. By adopting a volumetric ratio within this range, not only the linear expansion coefficient of the matrix can be controlled, but also, the matrix has an electric conductivity and a heat conductivity closer to of a metal rather than those of a pure ceramics. As a result, it is possible to apply voltage as well as bias to such a matrix. When the aluminum-based material composing the matrix comprises aluminum and silicon, the aluminum-based material should contain silicon in an amount within a range of from 12 to 35 vol. %, or preferably, from 16 to 35 vol. %, or more preferably, from 20 to 35 vol. % with a view to satisfying (xcex11xe2x88x923)xe2x89xa6xcex12xe2x89xa6(xcex11+3).
Or, the ceramics member composing the matrix may comprise silicon carbide (SiC); the aluminum-based material composing the matrix may comprise aluminum (Al) or aluminum (Al) and silicon (Si); and the material composing the ceramics layer may comprise Al2O3 or aluminum nitride (AlN). To adjust the linear expansion coefficient and electrical properties of the ceramics layer, for example, TiO2 may be added to the material composing the ceramics layer. In this case, it is desirable to select a volumetric ratio of silicon carbide to the aluminum-based material so as to satisfy (xcex11xe2x88x923)xe2x89xa6xcex12xe2x89xa6(xcex11+3). Or, the volumetric ratio of silicon carbide to the aluminum-based material should be within a range of from 40/60 to 80/20, or more preferably, from 60/40 to 70/30. By adopting a volumetric ratio within this range, not only the linear expansion coefficient of the matrix can be controlled, but also, the matrix has an electric conductivity and a heat conductivity closer to those of a metal rather than those of a pure ceramics. As a result, it is possible to apply voltage as well as bias to such a matrix. When the aluminum-based material composing the matrix comprises aluminum and silicon, the aluminum-based material should contain silicon in an amount within a range of from 12 to 35 vol. %, or preferably, from 16 to 35 vol. %, or more preferably, from 20 to 35 vol. % with a view to satisfying (xcex11xe2x88x923)xe2x89xa6xcex12xe2x89xa6(xcex11+3).
In the composite material, the substrate processing apparatus, or the substrate mounting stage of the invention, the ceramics layer should preferably be formed on the surface of the matrix by the flame spraying method, or attached to the surface of the matrix by brazing.
A method for manufacturing the composite material of the invention for achieving the foregoing object comprises:
(A) a step of filling the texture of the ceramics member with an aluminum-based material, thereby preparing a matrix composing the ceramics member having the texture filled with the aluminum-based material; and
(B) a step of providing a ceramics layer on the surface of the matrix.
Or, a method for manufacturing the composite material of the invention for achieving the foregoing object, which is a method for manufacturing a composite material composing a part of a processing apparatus for processing the substrate, comprising:
(A) a step of filling the texture of the ceramics member with an aluminum-based material, thereby preparing a matrix comprising the ceramics member having the texture filled with the aluminum-based material; and
(B) a step of providing a ceramics layer on the surface of the matrix.
In the substrate processing apparatus, for example, plasma etching, plasma CVD or sputtering is applied to the substrate. A part of the substrate processing apparatus made of the composite material may take the form of a substrate mounting stage having an electrostatic chucking function and provided with temperature control means in an embodiment. Or, in the substrate processing apparatus, for example, plasma etching or plasma CVD is applied to the substrate, and a part of the substrate processing apparatus made of the composite material may take the form of side walls and/or a ceiling plate of the substrate processing apparatus in another embodiment. Further, in the substrate processing apparatus, for example, plasma etching is applied to the substrate, and a part of the substrate processing apparatus made of the composite material may take the form of parallel and flat upper opposed electrodes in a further embodiment.
A method for manufacturing the substrate processing apparatus for achieving the foregoing object, which is the method for preparing the substrate processing apparatus for processing a substrate, wherein:
a part of the substrate processing apparatus is composed of a composite material consisting of a matrix comprising a ceramics member having a texture filled with an aluminum-based material and a ceramics layer provided on the surface of the matrix.
which comprises preparing the composite material by:
(A) a step of filling the texture of the ceramics member with an aluminum-based material, thereby preparing a matrix comprising the ceramics member having the texture filled with the aluminum-based material; and
(B) a step of providing a ceramics layer on the surface of the matrix.
In the substrate processing apparatus in the method for manufacturing the substrate processing apparatus of the invention, for example, plasma etching, plasma CVD or sputtering is applied to the substrate, and a part of the substrate processing apparatus made of the composite material may take the form of a substrate mounting stage having an electrostatic chucking function and provided with temperature control means in an embodiment. This method for manufacturing the substrate processing apparatus may sometimes be referred to hereafter as the manufacturing method of the substrate processing apparatus of the embodiment 1 of the invention. In this case, the substrate mounting stage may be used as an electrode, and the ceramics layer displays the electrostatic chucking function.
In the manufacturing method of the substrate processing apparatus of the embodiment 1 of the invention, it is desirable to arrange temperature control means on the substrate mounting stage, and further, this temperature control means should preferably comprise a heater. The heater may be arranged outside the composite material, or in the interior of the matrix. In the latter case, when assuming the matrix to have a linear expansion coefficient xcex11[unit: 10xe2x88x926], the material composing the heater should preferably have a linear expansion coefficient xcex1H[unit: 10xe2x88x926] satisfying (xcex11xe2x88x923)xe2x89xa6xcex1Hxe2x89xa6(xcex11+3). Further, the temperature control means should preferably comprise a piping for the flow of a temperature controlling heat medium arranged in the interior of the matrix. In this case, when assuming the matrix to have a linear expansion coefficient xcex11[unit: 10xe2x88x926], the piping should preferably have a linear expansion coefficient xcex1P[unit: 10xe2x88x926] satisfying (xcex11xe2x88x923)xe2x89xa6xcex1Pxe2x89xa6(xcex11+3).
Or, in the manufacturing method of the substrate processing apparatus of the invention, for example, plasma etching or plasma CVD is applied to the substrate, and a part of the substrate processing apparatus composed of the composite material may take the form of a side wall and/or a ceiling plate of the substrate processing apparatus method of the substrate processing apparatus may sometimes be hereafter referred to as the manufacturing method of the substrate processing apparatus of the embodiment 2 of the invention. In this case, temperature control means should preferably be provided on the side wall and/or the ceiling plate of the substrate processing apparatus, and further, the temperature control means should preferably comprise a heater. The heater may be arranged outside the composite material or in the interior of the matrix. In the latter case, when assuming the matrix to have a linear expansion coefficient xcex11[unit: 10xe2x88x926/K], the material composing the heater should preferably have a linear expansion coefficient xcex1H[unit: 10xe2x88x926/K] satisfying (xcex11xe2x88x923)xe2x89xa6xcex1Hxe2x89xa6(xcex11+3).
Or, in the substrate processing apparatus in the manufacturing method of the substrate processing apparatus of the invention, for example, plasma etching is applied to the substrate, and a part of the substrate processing apparatus made of the composite material may take the form of a parallel flat upper opposite electrode arranged in the substrate processing apparatus. This manufacturing method of the substrate processing apparatus may sometimes hereafter be referred to as the manufacturing method of the substrate processing apparatus of the embodiment 3 of the invention. In this case, temperature control means should preferably be provided for the upper opposite electrode, and further, the temperature control means should preferably comprise a heater. The heater may be arranged outside the composite material or in the interior of the matrix. In the latter case, when assuming the matrix to have a linear expansion coefficient xcex11[unit: 10xe2x88x926/K], the material composing the heater should preferably have a linear expansion coefficient xcex1H[unit: 10xe2x88x926/K] satisfying (xcex11xe2x88x923)xe2x89xa6xcex1Hxe2x89xa6(xcex11+3).
In the substrate processing apparatus, plasma etching may be applied to the substrate by the combination of the manufacturing method of the substrate processing apparatus of the embodiment 1 and the manufacturing method of the substrate processing apparatus of the embodiment 2, the combination of the manufacturing method of the substrate processing apparatus of the embodiment 1 and the manufacturing method of the substrate processing apparatus of the embodiment 3, the combination of the manufacturing method of the substrate processing apparatus of the embodiment 2 and the manufacturing method of the substrate processing apparatus of the embodiment 3, or the combination of the manufacturing method of the substrate processing apparatus of the embodiment 1, the manufacturing method of the substrate processing apparatus of the embodiment 2 and the manufacturing method of the substrate processing apparatus of the embodiment 3. In the substrate processing apparatus, when applying plasma CVD to the substrate, this may be achieved by the combination of the manufacturing method of the substrate processing apparatus of the embodiment 1 and the manufacturing method of the substrate processing apparatus of the embodiment 2.
A manufacturing method of the substrate mounting stage of the invention for achieving the foregoing object, which is a manufacturing method of the substrate mounting stage having an electrostatic chucking function and provided with temperature control means, wherein:
the substrate mounting stage is made of a composite material consisting of a matrix comprising a ceramics member having a texture filled with an aluminum-based material and a ceramics layer provided on the surface of the matrix,
which comprises preparing the composite material by:
(A) a step of filling the texture of the ceramics member with an aluminum-based material, thereby preparing a matrix comprising the ceramics member having the texture filled with the aluminum-base material; and
(B) a step of providing a ceramics layer on the surface of the matrix.
In the manufacturing method of the substrate mounting stage of the invention, the substrate mounting stage is used as an electrode, and the ceramics layer displays an electrostatic chucking function. Temperature control means should preferably be provided. Further, the temperature control means should preferably comprise a heater. The heater may be arranged outside the composite material, or in the interior of the matrix. In the latter case, when assuming the matrix to have a linear expansion coefficient xcex11[unit: 10xe2x88x926/K], the material composing the heater should preferably have a linear expansion coefficient xcex1H[unit: 10xe2x88x926/K] satisfying (xcex11xe2x88x923)xe2x89xa6xcex1Hxe2x89xa6(xcex11+3). Further, the temperature control means should preferably have a piping for the flow of a temperature controlling heat medium, provided in the interior of the matrix. In this case, when assuming the matrix to have a linear expansion coefficient xcex11[unit: 10xe2x88x926/K], the piping should preferably have a linear expansion coefficient xcex1P[unit: 10xe2x88x926/K] satisfying (xcex11xe2x88x923)xe2x89xa6xcex1Pxe2x89xa6(xcex11+3).
In the manufacturing method of the composite material, the manufacturing method of the substrate processing apparatus, and the manufacturing method of the substrate mounting stage of the invention, when assuming the matrix to have a linear expansion coefficient xcex11[unit: 10xe2x88x926/K], the ceramics layer should preferably have a linear expansion coefficient xcex12[unit: 10xe2x88x926/K] satisfying (xcex11xe2x88x923)xe2x89xa6xcex12xe2x89xa6(xcex11+3). As a result of xcex11 and xcex12 satisfying this relationship, it is possible to ensure prevention of damages to the ceramics layer such as cracks caused by the difference between the linear expansion coefficient xcex11 of the matrix and the linear expansion coefficient xcex12 of the ceramics layer.
In the manufacturing method of the composite material, the manufacturing method of the substrate processing apparatus, and the manufacturing method of the substrate mounting apparatus, the process (A) should preferably comprise the steps of placing a ceramics member comprising a porous cordierite ceramics in a vessel, casting an aluminum-based material comprising molten aluminum and silicon into the vessel, and filling the ceramics member with the aluminum-based material by the high-pressure coating method. In this case, the ceramics member is available by forming cordierite ceramics by, for example, the die press forming method, the hydrostatic forming method (also known as the CIP method or the rubber press forming method), the casting forming method (also known as the ship casting method), or the sludge casting method, and then, firing the formed product.
In this case, when assuming the matrix to have a linear expansion coefficient xcex11[unit: 10xe2x88x926/K], it is desirable to select a volumetric ratio of cordierite ceramics to the aluminum-based material so that the ceramics layer has a linear expansion coefficient xcex12[unit: 10xe2x88x926/K] satisfying (xcex11xe2x88x923)xe2x89xa6xcex12xe2x89xa6(xcex11+3). Or, the volumetric ratio of cordierite ceramics to the aluminum-based material should be within a range of from 25/75 to 75/25, or preferably, form 25/75 to 50/50. With the aluminum-based material as a reference, the aluminum-based material should preferably contain silicon in an amount within a range of from 12 to 35 vol. %, or preferably, from 16 to 35 vol. %, or more preferably, from 20 to 35 vol. % with a view to satisfying (xcex11xe2x88x923)xe2x89xa6xcex12xe2x89xa6(xcex11+3).
While a ceramics member can be prepared by forming cordierite ceramics powder and then firing the formed product, manufacture by firing a mixture of cordierite ceramics powder and cordierite ceramics fiber is preferable with a view to obtaining a porous ceramics member and preventing occurrence of damages to the ceramics member upon manufacture of the matrix. In the latter case, the ratio of cordierite ceramics fiber in the fired mixture should be within a range of from 1 to 20 vol. %, or preferably, from 1 to 10 vol. %, or more preferably, from 1 to 5 vol. %. The cordierite ceramics powder should have an average particle size within a range of from 100 xcexcm, or preferably, from 5 to 50 xcexcm, or more preferably, from 5 to 10 xcexcm. The cordierite ceramics fiber should have an average diameter within a range of from 2 to 10 xcexcm, or preferably, from 3 to 5 xcexcm, and an average length within a range of from 0.1 to 10 mm, or preferably, from 1 to 2 mm. Further, the mixture of cordierite ceramics powder and cordierite ceramics fiber should be fired at a temperature within a range of from 800 to 1,200xc2x0 C., or preferably, from 800 to 1,100xc2x0 C. The ceramics member should have a porosity within range of from 25 to 75%, or preferably, from 50 to 75%.
Upon casting the molten aluminum-based material into the vessel, the ceramics member should have a temperature within a range of from 500 to 1,000xc2x0 C., or preferably, from 700 to 800xc2x0 C. Also upon casting the molten aluminum-based material into the vessel, the aluminum-based material should have a temperature within a range of from 700 to 1,000xc2x0 C., or preferably, from 750 to 900xc2x0 C. Upon filling the ceramics member with the aluminum-based material by the high-pressure casting method, the applied absolute pressure should be within a range of from 200 to 1,500 Kgf/cm2, or preferably, from 800 to 1,000 Kgf/cm2.
Or, the process (A) should preferably comprise the step of causing the aluminum-based material comprising molten aluminum or aluminum and silicon penetrate into a member formed from aluminum nitride particles in accordance with the non-pressurized metal penetrating method. The ceramics member is available by forming by the die press forming method, the hydrostatic forming method, the casting forming method, or the sludge casting forming method, and then firing the formed product at a temperature within a range of from 500 to 1,000xc2x0 C., or preferably, from 800 to 1,000xc2x0 C. In this case, when assuming the matrix to have a linear expansion coefficient xcex11[unit: 10xe2x88x926/K], a volumetric ratio of aluminum nitride particles to the aluminum-based material should preferably be selected so that the ceramics layer has a linear expansion coefficient xcex12[unit: 10xe2x88x926/K] satisfying (xcex11xe2x88x923)xe2x89xa6xcex12xe2x89xa6(xcex11+3). Or, the volumetric ratio of aluminum nitride particles to the aluminum-based material should be within a range of from 40/60 to 80/20, or preferably, from 60/40 to 70/30. The aluminum nitride particles should have an average particle size within a range of from 10 to 100 xcexcm, or preferably, from 10 to 50 xcexcm, or more preferably, from 10 to 20 xcexcm. When the aluminum-based material composing the matrix comprises aluminum and silicon, the aluminum-based material should contain silicon in an amount within a range of from 12 to 35 vol. %, or preferably, from 16 to 35 vol. %, or more preferably, from 20 to 35 vol. %, with a view to satisfying (xcex11xe2x88x923)xe2x89xa6xcex12xe2x89xa6(xcex11+3).
Or, the process (A) should preferably comprise the step of causing the aluminum-based material comprising molten aluminum or aluminum and silicon in a non-pressurized state to penetrate into the ceramics member formed from silicon carbide particles in accordance with the non-pressurized metal penetrating method. Or, the process (A) should preferably comprise the steps of arranging a ceramics member comprising silicon carbide in a vessel, casting an aluminum-based material comprising molten aluminum or aluminum and silicon into the vessel, and filling the ceramics member with the aluminum-based material by the high-pressure casting method. In this case, upon casting the molten aluminum-based material into the vessel, the ceramics member should have a temperature within a range of from 500 to 1,000xc2x0 C., and upon filling the ceramics member with the aluminum-based material, the applied absolute pressure should preferably be within a range of from 200 to 1,500 Kgf/cm2. The ceramics member is available by forming by the die press forming method the hydrostatic forming method, the casting forming method, or the sludge casting forming method, and then firing the formed product at a temperature within a range of from 500 to 1,000xc2x0 C., or preferably, from 800 to 1,000xc2x0 C. In this case, when assuming the matrix to have a linear expansion coefficient xcex11[unit: 10xe2x88x926/K], a volumetric ratio of silicon carbide particles to the aluminum-based material should preferably be selected so that the ceramics layer has a linear expansion coefficient xcex12[unit: 10xe2x88x926/K] satisfying (xcex11xe2x88x923)xe2x89xa6xcex12xe2x89xa6(xcex11+3). Or, the volumetric ratio of silicon carbide particles to the aluminum-based material should be within a range of from 40/60 to 80/20, or preferably, from 60/40 to 70/30. The silicon carbide particles should have an average particle size within a range of from 1 to 100 FM, or preferably, from 10 to 80 xcexcm, or more preferably, from 15 to 60 xcexcm. When the aluminum-based material composing the matrix comprises aluminum and silicon, the aluminum-based material should contain silicon in an amount within a range of from 12 to 35 vol. %, or preferably, from 16 to 35 vol. %, or more preferably, from 20 to 35 vol. %, with a view to satisfying (xcex11xe2x88x923)xe2x89xa6xcex12xe2x89xa6(xcex11+3).
In the manufacturing method of the composite material, the manufacturing method of the substrate processing apparatus, and the manufacturing method of the substrate mounting stage of the invention, the material composing the ceramics layer may comprise Al2O3 or aluminum nitride (AlN). TiO2 may be added to the material composing the ceramics layer to adjust linear expansion coefficient and electrical properties of the ceramics layer. The process (B) should preferably comprise the step of forming the ceramics layer on the surface of the matrix by the flame spraying method. Or, the process (B) should preferably comprise the step of attaching the ceramics layer to the surface of the matrix by brazing.
In the method for processing a substrate of the embodiment 1 of the invention for achieving the foregoing object, which is method for processing the substrate by the use of the substrate processing apparatus for processing the substrate, the substrate processing apparatus has a substrate mounting stage. The substrate mounting stage is manufactured from a composite material consisting of a matrix comprising a ceramics member having a texture filled with an aluminum-based material, and a ceramics layer provided on the surface of the matrix. The substrate mounting stage has an electrostatic chucking function and is provided with temperature control means. It is characterized in that it fixes the substrate on the substrate mounting stage by means of the electrostatic chucking function, and processes the substrate in a state in which temperature of the substrate mounting stage is controlled by the temperature control means. This substrate processing method may sometimes be hereafter referred to as the substrate processing method of the embodiment 1 of the invention. In this case, the substrate may be processed by plasma etching, plasma CVD or sputtering. Sputtering may include soft etching of the substrate. Temperature of the substrate mounting stage upon processing the substrate should be controlled within a range of from room temperature to 650xc2x0 C., or preferably, from 100 to 400xc2x0 C., or more preferably, from 100 to 300xc2x0 C. for plasma etching; from room temperature to 650xc2x0 C., or preferably, from 100 to 500xc2x0 C., or more preferably, from 200 to 500xc2x0 C. for plasma CVD; and from room temperature to 650xc2x0 C., or preferably, from 200 to 600xc2x0 C., or more preferably, from 300 to 500xc2x0 C. for sputtering. Temperature control means should preferably be arranged on the substrate mounting stage, and the temperature control means should preferably comprise a heater. The heater may be arranged outside the composite material of in the interior of the matrix. The temperature control means should preferably comprise a piping for the flow of a temperature controlling heat medium. More specifically, the aforesaid substrate processing apparatus of the embodiment 1 of the invention may be employed as such a substrate processing apparatus.
Or, a substrate processing method of the embodiment 2 of the invention for achieving object is a substrate processing method using the substrate processing apparatus for processing a substrate in which a side wall and/or a ceiling plate are manufactured from a composite material consisting of a matrix comprising ceramics member having a texture filled with an aluminum-based material, and a ceramics layer provided on the surface of the matrix, and comprises the steps of housing the substrate in the substrate processing apparatus, and applying plasma etching or plasma CVD to the substrate. This substrate processing method may sometimes be referred to hereafter as the substrate processing method of the embodiment 2 of the invention. More specifically, it suffices to use the substrate processing apparatus of the foregoing embodiment 2 of the invention as the substrate processing apparatus. Upon applying plasma etching or plasma CVD to the substrate, temperature of the side wall and/or the ceiling plate should be controlled within a range of from room temperature to 650xc2x0 C., or preferably, from 100 to 400xc2x0 C., or more preferably, from 100 to 300xc2x0 C. for plasma etching; and from room temperature to 650xc2x0 C., or preferably, from 100 to 500xc2x0 C., or more preferably, from 200 to 500xc2x0 C. for plasma CVD. Temperature control means should preferably be provided for the side wall and/or the ceiling plate, and the temperature control means should preferably comprise a heater. Further, the heater may be arranged outside the composite material, but should preferably be arranged in the interior of the matrix.
Further, a substrate processing method of the embodiment 3 of the invention for achieving the foregoing object is a substrate processing method using the substrate processing apparatus for processing a substrate, in which the substrate processing apparatus is provided with a substrate mounting stage serving as a lower electrode and an upper opposite electrode; the upper opposite electrode is made of a composite material consisting of a matrix comprising a ceramics member having a texture filled with an aluminum-base material, and a ceramics layer provided on the surface of the matrix; and comprises the step of applying plasma etching to the substrate in a state in which the substrate is mounted on the substrate mounting stage. This substrate processing method may sometimes be referred to hereafter as the substrate processing method of the embodiment 3 of the invention. More specifically, it suffices to use the substrate processing apparatus of the foregoing embodiment 3 of the invention as the substrate processing apparatus. Upon applying plasma etching to the substrate, temperature of the upper opposite electrode should be controlled within a range of from room temperature to 400xc2x0 C., or preferably, from 50 to 400xc2x0 C., ore more preferably, from 200 to 350xc2x0 C. Temperature control means should preferably be provided for the upper opposed electrode; and the temperature control means should comprise a heater. Further, which the heater may be arranged outside the composite material, it should preferably be arranged in the interior of the matrix.
Plasma etching may be applied via the combination of the substrate processing method of the embodiment 1 and the substrate processing method of the embodiment 2, the combination of the substrate processing method of the embodiment 1 and the substrate processing method of the embodiment 3, the combination of the substrate processing method of the embodiment 2 and the substrate processing method of the embodiment 3, or the combination of the substrate processing method of the embodiment 1, the substrate processing method of the embodiment 2, and the substrate processing method of the embodiment 3. When applying plasma CVD to the substrate, the combination of the substrate processing method of the embodiment 1 and the substrate processing method of the embodiment 2 may be employed.
Substrate applicable in the invention include a silicon semiconductor substrate, a compound semiconductor or semi-insulating substrate such as a GaAs substrate, a semiconductor substrate having an SOI structure an insulating substrate, various insulating layer of insulating films formed on a semiconductor substrate or a semi-insulating substrate or an insulating film, a conductive thin film, a metal thin film, a metal compound thin film, and laminations thereof. Applicable insulating layers and insulating films include known materials such as SiO2, BPSG, PSG, BSG, AsSG, PbSG, NSG, SOG, LTO (Low Temperature Oxide: low-temperature CVD-SiO2), SiN and SiON, and laminations thereof. Applicable conductive thin films include polycrystalline silicon doped with impurities. Applicable metal thin films and metal compound thin films include Cu, Ti, TiN, BST (barium-strontium-titanium-oxide), STO (strontium-titanium oxide), SBT (strontium-barium-tantalum oxide), Pt, Al, aluminum alloys containing, for example, copper or silicon, high-melting-point metals such as tungsten, and various silicides. Further, materials in areas other than the semiconductor device manufacturing sector such as a copper film or a copper lamination formed on a plastic film such as a polyimide film is also applicable in the present invention.
In the present invention, the matrix is provided with properties coming between a ceramics member and an aluminum-based material by preparing the composite material with a matrix comprising a ceramics member having a texture filled with an aluminum-based material and a ceramics layer provide on the surface of the matrix, and as a result, it is possible to adjust the linear expansion coefficient to such a value coming between. It is therefore possible to avoid occurrence of damages to the ceramics layer caused by the difference in thermal expansion between the matrix and ceramics layer and to ensure application of the composite material at high temperatures. In addition, since the matrix has a high thermal conductivity, the substrate can be efficiently heated. Further, because the ceramics layer is provided, it is possible to prevent occurrence of metal contamination and to prevent occurrence of corrosion of the composite material caused by a halogen gas. By satisfying the relationship (xcex11xe2x88x923)xe2x89xa6xcex12xe2x89xa6(xcex11+3), it is possible to prevent almost perfectly occurrence of damages to the ceramics layer caused by the difference between the linear expansion coefficient xcex11 of the matrix and the linear expansion coefficient xcex12 of the ceramics layer.